Hermetic Sealing Of Hard Disk Drive Using Laminated Film Seal

ABSTRACT

A hermetically-sealed hard disk drive (HDD) utilizes a laminated film seal to seal an HDD cover-to-base interface. The laminated film seal may be constructed of a heat sealant layer hermetically-coupled to and forming a seal with the base, a barrier layer which inhibits gas from escaping from inside the HDD, and a film surface protective layer which protects the heat sealant and barrier layers. Embodiments may include a heat sealant layer comprising a thermoplastic polymer such as polypropylene, a barrier layer comprising a metal such as aluminum, and a film surface protective layer comprising a thermoplastic polymer such as polyethylene terephthalate.

FIELD OF EMBODIMENTS

Embodiments of the invention may relate generally to hard disk drivesand more particularly to use of a film laminate for hermetically sealinga hard disk drive.

BACKGROUND

A hard-disk drive (HDD) is a non-volatile storage device that is housedin a protective enclosure and stores digitally encoded data on one ormore circular disk having magnetic surfaces. When an HDD is inoperation, each magnetic-recording disk is rapidly rotated by a spindlesystem. Data is read from and written to a magnetic-recording disk usinga read-write head that is positioned over a specific location of a diskby an actuator. A read-write head uses a magnetic field to read datafrom and write data to the surface of a magnetic-recording disk. A writehead makes use of the electricity flowing through a coil, which producesa magnetic field. Electrical pulses are sent to the write head, withdifferent patterns of positive and negative currents. The current in thecoil of the write head induces a magnetic field across the gap betweenthe head and the magnetic disk, which in turn magnetizes a small area onthe recording medium.

HDDs are being manufactured which are hermetically sealed with heliuminside. Further, other gases that are lighter than air have beencontemplated for use as a replacement for air in sealed HDDs. There arevarious benefits to sealing and operating an HDD in helium ambient, forexample, because the density of helium is one-seventh that of air.Hence, operating an HDD in helium reduces the drag force acting on thespinning disk stack, and the mechanical power used by the disk spindlemotor is substantially reduced. Further, operating in helium reduces theflutter of the disks and the suspension, allowing for disks to be placedcloser together and increasing the areal density (a measure of thequantity of information bits that can be stored on a given area of disksurface) by enabling a smaller, narrower data track pitch. The lowershear forces and more efficient thermal conduction of helium also meanthe HDD will run cooler and will emit less acoustic noise. Thereliability of the HDD is also increased due to low humidity, lesssensitivity to altitude and external pressure variations, and theabsence of corrosive gases or contaminants.

Electronic systems that require a hermetically-sealed internal volume(e.g., a lighter-than-air gas filled, sealed HDD) need a way ofconnecting electrical lines through the enclosure. This may beaccomplished with a hermetic electrical connector, or electrical“feed-through”. One approach to hermetically sealing such an electricalfeed-through is to apply solder around the perimeter of the feed-throughnear where the feed-through interfaces with the HDD enclosure base.However, such a soldering process may be a relatively costly process inthe context of mass production of HDDs.

Another approach to connecting electrical lines through ahermetically-sealed HDD enclosure may involve routing of an electricalflexible cable assembly (or “flex cable”) directly through an opening inthe enclosure. However, this approach may also be a relatively costlyprocess in the context of mass production of HDDs, as well as posechallenges regarding achieving a robust hermetic seal.

Furthermore, electronic systems that require a hermetically-sealedinternal volume (e.g., a lighter-than-air gas filled, sealed HDD) need away of hermetically sealing the cover to the base. One approach is toutilize two covers, one being the typical HDD cover coupled to the basewith fasteners (a “first cover”) but not hermetically-sealed, withanother cover (a “second cover”) being welded to the base over the firstcover, such as by laser welding. However, once again such a solderingprocess is a relatively costly process in the context of mass productionof HDDs.

Any approaches described in this section are approaches that could bepursued, but not necessarily approaches that have been previouslyconceived or pursued. Therefore, unless otherwise indicated, it shouldnot be assumed that any of the approaches described in this sectionqualify as prior art merely by virtue of their inclusion in thissection.

SUMMARY OF EMBODIMENTS

Embodiments of the invention are generally directed at a hard disk drive(HDD) in which a laminated film seal is used to hermetically seal an HDDcover-to-base interface, and a method for sealing such an HDD. Thelaminated film seal may comprise (a) a heat sealant layer forming a sealwith the base, and possibly with the second cover, (b) a barrier layerwhich inhibits gas from escaping (or egressing) from inside the HDD, and(c) a film surface protective layer which protects the heat sealant andbarrier layers. Alternative embodiments include positioning thelaminated film over and bonding with a second cover, and positioning thelaminated film between first and second covers and bonding with thesecond cover and the base.

Embodiments may include a heat sealant layer comprising a thermoplasticpolymer, such as polypropylene for a non-limiting example; a barrierlayer comprising a metal, such as aluminum for a non-limiting example;and a film surface protective layer comprising a thermoplastic polymer,such as polyethylene terephthalate for a non-limiting example.

Embodiments discussed in the Summary of Embodiments section are notmeant to suggest, describe, or teach all the embodiments discussedherein. Thus, embodiments of the invention may contain additional ordifferent features than those discussed in this section. Furthermore, nolimitation, element, property, feature, advantage, attribute, or thelike expressed in this section, which is not expressly recited in aclaim, limits the scope of any claim in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments are illustrated by way of example, and not by way oflimitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 is a plan view illustrating a hard disk drive (HDD), according toan embodiment;

FIG. 2 is a cross-sectional side view illustrating an HDD electricalfeed-through interface;

FIG. 3 is a cross-sectional side view illustrating a laminated filmseal, according to an embodiment;

FIG. 4A is a perspective view illustrating an HDD electricalfeed-through connector interface, according to an embodiment;

FIG. 4B is a cross-sectional side view illustrating the HDD electricalfeed-through connector interface of FIG. 4A, according to an embodiment;

FIG. 5 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment;

FIG. 6A is a perspective view illustrating an HDD electrical flexiblecable assembly (FCA) interface, according to an embodiment;

FIG. 6B is a cross-sectional side view illustrating the HDD electricalFCA of FIG. 6A, according to an embodiment;

FIG. 7 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment;

FIG. 8A is an exploded perspective view of a hermetically-sealed HDDhaving a second cover, according to an embodiment;

FIG. 8B is a cross-sectional side view illustrating thehermetically-sealed HDD of FIG. 8A, according to an embodiment;

FIG. 9A is an exploded perspective view of a hermetically-sealed HDDhaving a second cover, according to an embodiment;

FIG. 9B is a cross-sectional side view illustrating thehermetically-sealed HDD of FIG. 9A, according to an embodiment; and

FIG. 10 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment.

DETAILED DESCRIPTION

Approaches to a laminated film seal for a hermetically-sealed hard diskdrive are described. In the following description, for the purposes ofexplanation, numerous specific details are set forth in order to providea thorough understanding of the embodiments of the invention describedherein. It will be apparent, however, that the embodiments of theinvention described herein may be practiced without these specificdetails. In other instances, well-known structures and devices are shownin block diagram form in order to avoid unnecessarily obscuring theembodiments of the invention described herein.

Physical Description of an Illustrative Operating Context

Embodiments may be used in the context of a hermetic seal for a harddisk drive (HDD) storage device. Thus, in accordance with an embodiment,a plan view illustrating an HDD 100 is shown in FIG. 1 to illustrate anexemplary operating context.

FIG. 1 illustrates the functional arrangement of components of the HDD100 including a slider 110 b that includes a magnetic read-write head110 a. Collectively, slider 110 b and head 110 a may be referred to as ahead slider. The HDD 100 includes at least one head gimbal assembly(HGA) 110 including the head slider, a lead suspension 110 c attached tothe head slider typically via a flexure, and a load beam 110 d attachedto the lead suspension 110 c. The HDD 100 also includes at least onerecording medium 120 rotatably mounted on a spindle 124 and a drivemotor (not visible) attached to the spindle 124 for rotating the medium120. The read-write head 110 a, which may also be referred to as atransducer, includes a write element and a read element for respectivelywriting and reading information stored on the medium 120 of the HDD 100.The medium 120 or a plurality of disk media may be affixed to thespindle 124 with a disk clamp 128.

The HDD 100 further includes an arm 132 attached to the HGA 110, acarriage 134, a voice-coil motor (VCM) that includes an armature 136including a voice coil 140 attached to the carriage 134 and a stator 144including a voice-coil magnet (not visible). The armature 136 of the VCMis attached to the carriage 134 and is configured to move the arm 132and the HGA 110 to access portions of the medium 120, all collectivelymounted on a pivot shaft 148 with an interposed pivot bearing assembly152. In the case of an HDD having multiple disks, the carriage 134 maybe referred to as an “E-block,” or comb, because the carriage isarranged to carry a ganged array of arms that gives it the appearance ofa comb.

An assembly comprising a head gimbal assembly (e.g., HGA 110) includinga flexure to which the head slider is coupled, an actuator arm (e.g.,arm 132) and/or load beam to which the flexure is coupled, and anactuator (e.g., the VCM) to which the actuator arm is coupled, may becollectively referred to as a head stack assembly (HSA). An HSA may,however, include more or fewer components than those described. Forexample, an HSA may refer to an assembly that further includeselectrical interconnection components. Generally, an HSA is the assemblyconfigured to move the head slider to access portions of the medium 120for read and write operations.

With further reference to FIG. 1, electrical signals (e.g., current tothe voice coil 140 of the VCM) comprising a write signal to and a readsignal from the head 110 a, are transmitted by a flexible cable assembly(FCA) 156 (or “flex cable”). Interconnection between the flex cable 156and the head 110 a may include an arm-electronics (AE) module 160, whichmay have an on-board pre-amplifier for the read signal, as well as otherread-channel and write-channel electronic components. The AE module 160may be attached to the carriage 134 as shown. The flex cable 156 may becoupled to an electrical-connector block 164, which provides electricalcommunication, in some configurations, through an electricalfeed-through provided by an HDD housing 168. The HDD housing 168 (or“enclosure base” or simply “base”), in conjunction with an HDD cover,provides a semi-sealed (or hermetically-sealed, in some configurations)protective enclosure for the information storage components of the HDD100.

Other electronic components, including a disk controller and servoelectronics including a digital-signal processor (DSP), provideelectrical signals to the drive motor, the voice coil 140 of the VCM andthe head 110 a of the HGA 110. The electrical signal provided to thedrive motor enables the drive motor to spin providing a torque to thespindle 124 which is in turn transmitted to the medium 120 that isaffixed to the spindle 124. As a result, the medium 120 spins in adirection 172. The spinning medium 120 creates a cushion of air thatacts as an air-bearing on which the air-bearing surface (ABS) of theslider 110 b rides so that the slider 110 b flies above the surface ofthe medium 120 without making contact with a thin magnetic-recordinglayer in which information is recorded. Similarly in an HDD in which alighter-than-air gas is utilized, such as helium for a non-limitingexample, the spinning medium 120 creates a cushion of gas that acts as agas or fluid bearing on which the slider 110 b rides.

The electrical signal provided to the voice coil 140 of the VCM enablesthe head 110 a of the HGA 110 to access a track 176 on which informationis recorded. Thus, the armature 136 of the VCM swings through an arc180, which enables the head 110 a of the HGA 110 to access varioustracks on the medium 120. Information is stored on the medium 120 in aplurality of radially nested tracks arranged in sectors on the medium120, such as sector 184. Correspondingly, each track is composed of aplurality of sectored track portions (or “track sector”) such assectored track portion 188. Each sectored track portion 188 may includerecorded information, and a header containing error correction codeinformation and a servo-burst-signal pattern, such as anABCD-servo-burst-signal pattern, which is information that identifiesthe track 176. In accessing the track 176, the read element of the head110 a of the HGA 110 reads the servo-burst-signal pattern, whichprovides a position-error-signal (PES) to the servo electronics, whichcontrols the electrical signal provided to the voice coil 140 of theVCM, thereby enabling the head 110 a to follow the track 176. Uponfinding the track 176 and identifying a particular sectored trackportion 188, the head 110 a either reads information from the track 176or writes information to the track 176 depending on instructionsreceived by the disk controller from an external agent, for example, amicroprocessor of a computer system.

An HDD's electronic architecture comprises numerous electroniccomponents for performing their respective functions for operation of anHDD, such as a hard disk controller (“HDC”), an interface controller, anarm electronics module, a data channel, a motor driver, a servoprocessor, buffer memory, etc. Two or more of such components may becombined on a single integrated circuit board referred to as a “systemon a chip” (“SOC”). Several, if not all, of such electronic componentsare typically arranged on a printed circuit board that is coupled to thebottom side of an HDD, such as to HDD housing 168.

References herein to a hard disk drive, such as HDD 100 illustrated anddescribed in reference to FIG. 1, may encompass an information storagedevice that is at times referred to as a “hybrid drive”. A hybrid driverefers generally to a storage device having functionality of both atraditional HDD (see, e.g., HDD 100) combined with solid-state storagedevice (SSD) using non-volatile memory, such as flash or othersolid-state (e.g., integrated circuits) memory, which is electricallyerasable and programmable. As operation, management and control of thedifferent types of storage media typically differ, the solid-stateportion of a hybrid drive may include its own corresponding controllerfunctionality, which may be integrated into a single controller alongwith the HDD functionality. A hybrid drive may be architected andconfigured to operate and to utilize the solid-state portion in a numberof ways, such as, for non-limiting examples, by using the solid-statememory as cache memory, for storing frequently-accessed data, forstoring I/O intensive data, and the like. Further, a hybrid drive may bearchitected and configured essentially as two storage devices in asingle enclosure, i.e., a traditional HDD and an SSD, with either one ormultiple interfaces for host connection.

Introduction

The term “hermetic” will be understood to describe a sealing arrangementdesigned to have nominally no (or negligible) gaseous leakage orpermeation paths. While terms such as “hermetic”, “negligible leakage”,“no leakage”, etc. may be used herein, note that such a system wouldoften still have a certain amount of permeability and, therefore, not beabsolutely leak-free.

Recall that with a hermetically-sealed hard disk drive (HDD) there needsto be a way of connecting electrical lines through the enclosure, suchas to an onboard printed circuit board that is external to the sealedvolume of the enclosure, and this may be accomplished with a hermeticelectrical feed-through soldered to the HDD base, an example of whichfollows.

FIG. 2 is a cross-sectional side view illustrating an HDD electricalfeed-through interface. Hermetically-sealed HDD 200 comprises anenclosure base 202 coupled with an HDD cover 204, thereby enclosing asealed internal space 205. In order to electrically connect a flexiblecable assembly 208 that is located inside the internal space 205 with aprinted circuit board (PCB) 210 that is coupled to the base 202 outsideof the internal space 205, a hermetic electrical connector 206 (or“feed-through” or “feed-through connector”) is used at the interfacebetween the internal space 205 and the external environment, i.e., at anorifice of the base 202. The connector 206 is attached to the base 202using solder 207. In the configuration depicted in FIG. 2, the connector206 is shown soldered to the underside of the base 202. While effectivehermetically, the foregoing sealing arrangement may not be the mostcost-effective approach.

Recall also that another approach to connecting electrical lines througha hermetically-sealed HDD enclosure may involve routing of an electricalflexible cable assembly (or “flex cable”) directly through an opening inthe enclosure, but that this approach may also pose challenges withachieving a robust hermetic seal.

Recall also that electronic systems that require a hermetically-sealedinternal volume may also need a way of hermetically sealing the cover tothe base, which may involve welding of a second cover to the base, overthe first cover, to achieve a hermetic seal, but that this approach maynot be the most cost-effective approach either.

Laminated Film Seal for Hermetically-Sealed Hard Disk Drive

An approach to sealing a hard disk drive, for example, sealing a harddisk drive (HDD) around its electrical feed-through interface, involvesthe use of a laminated film seal structure.

FIG. 3 is a cross-sectional side view illustrating a laminated filmseal, according to an embodiment. A laminated film seal (or “seallaminate”) relies on a laminated film structure to provide a hermeticseal. According to an embodiment, a laminated film seal is created basedon a heat-sealing film or laminate bonded to at least one surface 301.

Laminated film 300 comprises a heat sealant layer 302 capable of forminga bond with another surface through the use of a heat-sealing process,e.g., based on corresponding ranges of temperature and pressure. Heatsealant layer 302 is covered by a barrier layer 304, which is designedto inhibit the escape (or “egress” or “diffusion”) of gas through thelaminated film 300, i.e., to be hermetically permeable (or“impermeable”). Barrier layer 304 is covered by a film surfaceprotective layer 306, which is designed to protect the heat sealantlayer 302 and the barrier layer 304. Other additional layers may also bepresent in a laminated film such as laminated film 300, the material andstructure of which may vary from implementation to implementation. Forexample, a metal adhesive layer with a polymeric base material may beimplemented instead of or in addition to the heat sealant layer 302, orthe heat sealant layer 302 may be constituent to a metal adhesive layer.In the case of a hermetically-sealed HDD, the laminated film 300 shouldbe designed and configured to inhibit the egress of helium (He),nitrogen (N), or whatever lighter-than-air gas may be used within thesealed HDD.

According to an embodiment, the heat sealant layer 302 comprises athermoplastic polymer or resin, such as polypropylene (also known aspolypropene) [chemical formula=(C₃H₆)_(n)], polyethylene (also known aspolyethene) [chemical formula=(C₂H₄)_(n)], and like polymers. Accordingto a related embodiment, the heat sealant layer 302 comprisespolypropylene.

According to an embodiment, the barrier layer 304 comprises a metal,such as aluminum, stainless steel, copper, and the like, having arelatively low permeability in relation to the target lighter-than-airgas being used to fill an HDD. According to a related embodiment, thebarrier layer 304 comprises aluminum.

According to an embodiment, the barrier layer 304 comprises a copolymeror resin, such as ethylene vinyl alcohol (EVOH) [chemicalformula=(C₂H₄O—C₂H₄)_(x)].

According to an embodiment, the film surface protective layer 306comprises a thermoplastic polymer or resin, such as polyethyleneterephthalate (PET) [chemical formula=(C₁₀H₈O₄)_(n)], polypropylene, andlike polymers. According to a related embodiment, the heat sealant layer302 comprises PET.

Laminated Film Seal for Electrical Feed-Through Connector

FIG. 4A is a perspective view illustrating an HDD electricalfeed-through connector interface, according to an embodiment. Interface400 is depicted as comprising an HDD enclosure base 402 (outside shown),with which a hermetic electrical connector 406 is coupled, and wherebythe interface 400 is sealed with a laminated film 407. According toembodiments, laminated film 407 is constructed as illustrated anddescribed in reference to laminated film 300 (FIG. 3).

FIG. 4B is a cross-sectional side view illustrating the HDD electricalfeed-through connector interface of FIG. 4A, according to an embodiment.Again, interface 400 is depicted as comprising the HDD enclosure base402 with which the hermetic electrical connector 406 is coupled, andwhereby the interface 400 is sealed with the laminated film 407,constructed as illustrated and described in reference to laminated film300 (FIG. 3), and bonded with a surface of the base 402 and a surface ofthe electrical connector 406. According to an embodiment and asdepicted, the seal corresponding to laminated film 407 is positioned atthe interface 400 such that the laminated film 407 overlaps with both ofthe surfaces of the base 402 and the electrical connector 406. Hence,the laminated film 407 encircles the outer perimeter of the electricalconnector 406, as depicted in FIGS. 4A, 4B.

A First Method of Sealing a Hard Disk Drive

FIG. 5 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment.

At block 502, an electrical feed-though connector is mated with a harddisk drive (HDD) enclosure base at an interface between an HDD internalspace and an external environment. For example, hermetic electricalconnector 406 (FIGS. 4A, 4B) is suitably positioned to mate with HDDenclosure base 402. As depicted in FIG. 4B, the connector 406 may bemated with the base 402 from the external side, i.e., from the outsideof the HDD. However, precisely how the connector 406 is mated with thebase 402 may vary from implementation to implementation.

At block 504, a laminated film is positioned to overlap with a portionof the base and a portion of the feed-through connector, where thelaminated film comprises (a) a heat sealant layer, (b) a barrier layerthat can inhibit the egress of gas from the internal space, and (c) afilm surface protective layer protecting the heat sealant and barrierlayers. For example, laminated film 407 (FIGS. 4A, 4B), structurallyconfigured similarly to how illustrated and described in reference tolaminated film 300 of FIG. 3, is positioned to overlap with a portion ofthe enclosure base 402 (FIGS. 4A, 4B) and a portion of the feed-throughconnector 406 (FIGS. 4A, 4B), like is illustrated in FIGS. 4A, 4B.According to an embodiment, the laminated film is positioned to encirclethe outer perimeter of the feed-through connector, similar to asdepicted in FIG. 4A, for example.

At block 506, the laminated film is bonded to the portion of the baseand the portion of the feed-through connector by applying heat andpressure to the laminated film. Hence, a laminated film seal is formedby such a bonding process. For example, a heat-sealing bar that appliesheat and pressure is positioned in suitable relation with laminated film407 (FIGS. 4A, 4B) such that the heat sealant layer (e.g., heat sealantlayer 302 of laminated film 300 of FIG. 3) bonds to the base 402 (FIGS.4A, 4B) and the connecter 406 (FIGS. 4A, 4B). Heat-sealing (or heatsealant) materials, such as polypropylene, and heat-sealing films aresuch that they seal to a surface in response to a suitable range of heatand pressure.

Laminated Film Seal for Electrical Flexible Cable Assembly

FIG. 6A is a perspective view illustrating an HDD electrical flexiblecable assembly (FCA) interface, according to an embodiment. Interface600 is depicted as comprising an HDD enclosure base 602 (outside shown),with which an electrical flexible cable assembly (FCA) 608 is coupled inorder to provide an electrical path from the HDD internal space throughthe base 602 to the outside environment. The interface 600 is sealedwith a laminated film 607.

According to an embodiment, FCA 608 comprises an electrical conductorlayer 608 a coupled to a base film 608 b, and laminated film 607 isconstructed as illustrated and described in reference to laminated film300 (FIG. 3). According to an embodiment, the base film 608 b comprisesa polypropylene material, which is less hygroscopic than a polyimidematerial and, therefore, provides for a more moisture-resistant HDD.According to an embodiment, the laminated film 607 is positioned over aportion of the FCA 608 and functions to seal the interface 600 of theFCA 608 and the base 602.

FIG. 6B is a cross-sectional side view illustrating the HDD electricalFCA of FIG. 6A, according to an embodiment. Interface 600 is depicted ascomprising the HDD enclosure base 602 having a hole 601 through whichthe FCA 608 is routed between the internal space (e.g., internal side)and the outside environment (e.g., external side). As the interface 600is sealed with the laminated film 607, which overlaps and mates with aportion of the FCA 608 and part of the base 602, a heat sealant layer(e.g., heat sealant layer 302 of FIG. 3) of the laminated film 607 isconstructed and positioned to bond with the base 602 and with the FCA608. According to an embodiment, the remainder of the laminated film 607may be constructed as illustrated and described in reference to FIG. 3.

There are multiple approaches to the construction of the FCA 608.According to one embodiment, FCA 608 comprises a cover layer 608 c overthe electrical conductor layer 608 a, and the laminated film 607 ispositioned over and bonded with at least a portion of the cover layer608 c of FCA 608. According to an embodiment, the cover layer 608 c isconstructed of a thermoplastic polymer (or resin). According to arelated embodiment, the cover layer 608 c of the FCA 608 and the heatsealant layer (e.g., heat sealant layer 302 of FIG. 3) of the laminatedfilm 607 both comprise polypropylene, thereby facilitating a bondbetween the heat sealant layer and the cover layer 608 c, as well aswith the base 602, upon application of suitable heat and pressure forheat-seal bonding.

Another approach to the construction of the FCA 608 is one in which theFCA 608 does not comprise a cover layer over the electrical conductorlayer. Rather, and according to an embodiment, a metal adhesive layer610 is positioned between the base 602 and the FCA 608, and thelaminated film 607 is positioned over and bonded with at least a portionof the metal adhesive layer 610, in addition to the electrical conductorlayer 608 a, the base film 608 b, and the base 602.

A Second Method of Sealing a Hard Disk Drive

FIG. 7 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment.

At block 702, an electrical flexible cable assembly (FCA) is positionedthrough an HDD enclosure base at an interface of an HDD internal spaceand an outside environment, where the FCA comprises a base film and anelectrical conductor layer coupled to the base film. For example, FCA608 (FIGS. 6A, 6B) is positioned through the hole 601 (FIG. 6B) of thebase 602 (FIGS. 6A, 6B), where the hole 601 extends between the internalside and the external side of the base 602. Continuing with the example,FCA 608 is constructed of the electrical conductor layer 608 a (FIGS.6A, 6B) coupled to the base film 608 b (FIGS. 6A, 6B).

At block 704, a laminated film is positioned to overlap with a portionof the base and a portion of the FCA, where the laminated film comprises(a) a heat sealant layer, (b) a barrier layer that can inhibit theegress of gas from the internal space, and (c) a film surface protectivelayer protecting the heat sealant and barrier layers. For example,laminated film 607 (FIGS. 6A, 6B), according to an embodimentstructurally configured similarly to how illustrated and described inreference to laminated film 300 of FIG. 3, is positioned to overlap witha portion of the enclosure base 602 (FIGS. 6A, 6B) and a portion of theFCA 608 (FIGS. 6A, 6B), like is illustrated in FIGS. 6A, 6B.

At block 706, the laminated film is bonded to the portion of the baseand the portion of the FCA by applying heat and pressure to thelaminated film. Hence, a laminated film seal is formed by such a bondingprocess. For example, a heat-sealing bar that applies heat and pressureis positioned in suitable relation with laminated film 607 (FIGS. 6A,6B) such that the heat sealant layer (e.g., heat sealant layer 302 oflaminated film 300 of FIG. 3) bonds to the base 602 (FIGS. 6A, 6B) andto the FCA 608 (FIGS. 6A, 6B). According to an embodiment, a metaladhesive layer 610 (FIG. 6B) is positioned and applied between theexternal side of the base 602 and the base film 608 b of the FCA 608,such that the heat-sealing procedure causes the laminated film 607 tobond with the base 602 and with the metal adhesive layer 610, a portionover which the laminated film 607 is positioned. According to anotherembodiment, FCA 608 further comprises the cover layer 608 c (FIG. 6B)over the electrical conductor layer 608 a and the base film 608 b, suchthat the heat-sealing procedure causes the laminated film 607 to bondwith the base 602 and with the cover layer 608 c of FCA 608.

Laminated Film Seal for Hermetically-Sealed Hard Disk Drive Cover

FIG. 8A is an exploded perspective view of a hermetically-sealed HDDhaving a second cover, according to an embodiment. Hermetically-sealedHDD 800 comprises a first cover 804 attached to an HDD enclosure base802, and a second cover 806 positioned over the first cover 804.According to an embodiment, a laminated film 807, constructed asillustrated and described in reference to laminated film 300 (FIG. 3),is positioned over the second cover 806. FIG. 8A further depicts thateach of the second cover 806 and the laminated film 807 have a smallhole 811, 813, respectively, through which gas may be injected into theinternal space of the HDD 800. Once the gas injection process iscompleted, a small pin 808 may be used to plug the hole 811 in thesecond cover 806 and the hole 813 in the laminated film 807.

The second cover 806 provides a low-permeability barrier to the egressof the gas contained within the internal space of HDD 800. For example,second cover 806 may be constructed of a metal, through which gas isrelatively (although not absolutely) impermeable. However, the secondcover 806 still needs to be hermetically-sealed with the base 802, i.e.,the interface between the second cover 806 and the base 802 needs to besealed. Hence, according to an embodiment, the laminated film 807 isutilized to hermetically seal the second cover 806 to the base 802. Thatis, the heat sealant layer (e.g., heat sealant layer 302 of FIG. 3)covers the second cover 806 and is heat-sealed to a portion of the base802. The heat sealant layer may be further heat-sealed to the surface ofthe second cover 806.

FIG. 8B is a cross-sectional side view illustrating thehermetically-sealed HDD of FIG. 8A, according to an embodiment.Hermetically-sealed HDD 800 is again depicted as comprising the HDDenclosure base 802, over which the second cover 806 is positioned, andover which the laminated film 807 is positioned. According to anembodiment, the laminated film 807 comprises (a) a planar portion 807 athat is positioned substantially or relatively parallel with the secondcover 806, e.g., the laminated film is laid upon the second cover 806,and (b) at least one sidewall portion 807 b that is substantially normalto the planar portion 807 a, and is positioned to mate with acorresponding sidewall 802 b of the base 802. As the cover-to-baseinterface is sealed with the laminated film 807 upon application ofsuitable heat and pressure, the planar portion 807 a of which overlapswith second cover 806 and the sidewall portion 807 b of which overlapswith the sidewall 802 b of the base 802, a heat sealant layer (e.g.,heat sealant layer 302 of FIG. 3) of the laminated film 807 isconstructed and positioned to bond with the sidewall 802 b of the base802. According to an embodiment, the heat sealant layer may be furtherheat-sealed to the surface of the second cover 806, such that the heatsealant layer is bonded with a sidewall 806 b of the second cover 806and bonded with the sidewall 802 b of the base 802.

FIG. 9A is an exploded perspective view of a hermetically-sealed HDDhaving a second cover, according to an embodiment. Hermetically-sealedHDD 900 comprises a first cover 904 attached to an HDD enclosure base902, and a second cover 906 positioned over the first cover 904.According to an embodiment, a laminated film 907, constructed asillustrated and described in reference to laminated film 300 (FIG. 3),is positioned between the first cover 904 and the second cover 906.According to an embodiment and as generally depicted in FIG. 9A, thelaminated film 907 may be fabricated into a shape that mates with theouter perimeter surface of the base 902 as well as the outer perimeterarea of the second cover 906. Thus, with such a shape, the laminatedfilm 907 can function like a gasket seal between the base 902 and thesecond cover 906. FIG. 9A further depicts that the second cover 906 hasa small hole 911 through which gas may be injected into the internalspace of the HDD 900. Once the gas injection process is completed, asmall pin 908 may be used to plug the hole 911 in the second cover 906.

The second cover 906 provides a low-permeability barrier to the egressof the gas contained within the internal space of HDD 900. For example,second cover 906 may be constructed of a metal, through which gas isrelatively (although not absolutely) impermeable. However, the secondcover 906 still needs to be hermetically-sealed with the base 902, i.e.,the interface between the second cover 906 and the base 902 needs to besealed. Hence, according to an embodiment, the laminated film 907 isutilized to hermetically seal the second cover 906 to the base 902. Thatis, the heat sealant layer (e.g., heat sealant layer 302 of FIG. 3)overlaps with the first cover 904 and is below the second cover 906, andis therefore heat-sealed to the second cover 906 and heat-sealed to aportion of the base 902.

FIG. 9B is a cross-sectional side view illustrating thehermetically-sealed HDD of FIG. 9A, according to an embodiment.Hermetically-sealed HDD 900 is again depicted as comprising the HDDenclosure base 902, over which the laminated film 907 is positioned, andover which the second cover 906 is positioned. According to anembodiment, the laminated film 907 further comprises a metal adhesivelayer, which is positioned to mate and cohesively bond with acorresponding area of the second cover 906 and of the base 902 uponapplication of suitable heat and pressure.

A Third Method of Sealing a Hard Disk Drive

FIG. 10 is a flow diagram illustrating a method of sealing an HDD,according to an embodiment.

At block 1002, a first cover is coupled to an enclosure base. Forexample, first cover 804 (FIG. 8A) is coupled to the base 802 (FIGS. 8A,8B), or first cover 904 (FIG. 9A) is coupled to the base 902 (FIGS. 9A,9B).

At block 1004, a second cover, positioned over the first cover, is matedwith the base. For example, second cover 806 (FIGS. 8A, 8B) is matedwith the base 802 (FIGS. 8A, 8B), or second cover 906 (FIGS. 9A, 9B) ismated with the base 902 (FIGS. 9A, 9B).

At blocks 1006 a, 1006 b, a laminated film is positioned to overlap witha cover, where the laminated film comprises (a) a heat sealant layer,(b) a barrier layer that can inhibit the egress of gas from the internalspace, and (c) a film surface protective layer protecting the heatsealant and barrier layers. For example, at block 1006 a, laminated film807 (FIGS. 8A, 8B), according to an embodiment structurally configuredsimilarly to how illustrated and described in reference to laminatedfilm 300 of FIG. 3, is positioned to overlap with the second cover 806(FIGS. 8A, 8B). For another example, at block 1006 b, laminated film 907(FIGS. 9A, 9B), according to an embodiment structurally configuredsimilarly to how illustrated and described in reference to laminatedfilm 300 of FIG. 3, is positioned to overlap with the first cover 904(FIGS. 9A, 9B) but underneath the second cover 906 (FIGS. 9A, 9B).

At block 1008, the laminated film is bonded to the second cover byapplying suitable heat and pressure to the laminated film. Hence, alaminated film seal is formed by such a bonding process. For example, aheat-sealing bar that applies heat and pressure is positioned insuitable relation with laminated film 807 (FIGS. 8A, 8B), positioned tooverlap with the second cover 806 (FIGS. 8A, 8B), such that the heatsealant layer (e.g., heat sealant layer 302 of laminated film 300 ofFIG. 3) bonds to the second cover 806. Further, as described andillustrated in reference to FIG. 8B, the laminated film 807 may befolded or bent over a portion of the sides of the base 802 (FIGS. 8A,8B), thereby bonding with the sidewall 802 b (FIGS. 8A, 8B) of the base802, and possibly also with the sidewall 806 b of the second cover 806,upon application of suitable heat and pressure. For another example,laminated film 907 (FIGS. 9A, 9B), positioned to overlap with at least aportion of the first cover 904 (FIGS. 9A, 9B) and the base 902 (FIGS.9A, 9B) but underneath the second cover 906 (FIGS. 9A, 9B), is bondedwith the second cover 906 and to the base 902.

Extensions and Alternatives

In the foregoing description, embodiments of the invention have beendescribed with reference to numerous specific details that may vary fromimplementation to implementation. Therefore, various modifications andchanges may be made thereto without departing from the broader spiritand scope of the embodiments. Thus, the sole and exclusive indicator ofwhat is the invention, and is intended by the applicants to be theinvention, is the set of claims that issue from this application, in thespecific form in which such claims issue, including any subsequentcorrection. Any definitions expressly set forth herein for termscontained in such claims shall govern the meaning of such terms as usedin the claims. Hence, no limitation, element, property, feature,advantage or attribute that is not expressly recited in a claim shouldlimit the scope of such claim in any way. The specification and drawingsare, accordingly, to be regarded in an illustrative rather than arestrictive sense.

In addition, in this description certain process steps may be set forthin a particular order, and alphabetic and alphanumeric labels may beused to identify certain steps. Unless specifically stated in thedescription, embodiments are not necessarily limited to any particularorder of carrying out such steps. In particular, the labels are usedmerely for convenient identification of steps, and are not intended tospecify or require a particular order of carrying out such steps.

1. A hermetically-sealed hard disk drive having an internal space, thehard disk drive comprising: an enclosure base; a first cover coupled tosaid base; a second cover positioned over said first cover and coupledto said base; a laminated film comprising: a heat sealant layerhermetically-coupled with said base, wherein said heat sealant layer iscomposed of a material that forms a heat seal with a mating surface uponapplication of a sufficient amount of heat to said heat sealant layer, abarrier layer inhibiting escape of gas from said internal space, and afilm surface protective layer protecting said heat sealant and barrierlayers; and a heat seal formed from said heat sealant layer of saidlaminated film.
 2. The hermetically-sealed hard disk drive of claim 1,wherein said laminated film is positioned over said second cover andbonded with at least a portion of said second cover.
 3. Thehermetically-sealed hard disk drive of claim 1, wherein said laminatedfilm is positioned over said second cover and comprises: a planarportion positioned substantially parallel with said second cover, and atleast one sidewall portion substantially normal to said planar portionand mating with a corresponding sidewall of said base; and wherein saidheat sealant layer is bonded with said sidewall of said base.
 4. Thehermetically-sealed hard disk drive of claim 1, wherein said secondcover comprises a sidewall extending from a planar portion and matingwith a corresponding sidewall of said base, and wherein said laminatedfilm is positioned over said second cover and comprises: a planarportion positioned substantially parallel with said second cover, and atleast one sidewall portion substantially normal to said planar portionand mating with a corresponding sidewall of said second cover and acorresponding sidewall of said base; and wherein said heat sealant layeris bonded with said sidewall of said second cover and with said sidewallof said base.
 5. The hermetically-sealed hard disk drive of claim 1,wherein said laminated film is positioned between said first cover andsaid second cover and is bonded with at least a portion of said base. 6.The hermetically-sealed hard disk drive of claim 1, wherein saidlaminated film is positioned between said first cover and said secondcover and is bonded with said second cover and with at least a portionof said base.
 7. The hermetically-sealed hard disk drive of claim 1,wherein said laminated film further comprises a metal adhesive layer;and wherein said laminated film is positioned between said first coverand said second cover and said metal adhesive layer is bonded with saidsecond cover and with at least a portion of said base.
 8. Thehermetically-sealed hard disk drive of claim 1, wherein said heatsealant layer comprises a thermoplastic polymer.
 9. Thehermetically-sealed hard disk drive of claim 1, wherein said heatsealant layer comprises polypropylene.
 10. The hermetically-sealed harddisk drive of claim 1, wherein said barrier layer comprises a metal. 11.The hermetically-sealed hard disk drive of claim 1, wherein said barrierlayer comprises aluminum.
 12. The hermetically-sealed hard disk drive ofclaim 1, wherein said film surface protective layer comprises athermoplastic polymer.
 13. The hermetically-sealed hard disk drive ofclaim 1, wherein said film surface protective layer comprisespolyethylene terephthalate.
 14. The hermetically-sealed hard disk driveof claim 1, wherein said heat sealant layer comprises polypropylene;wherein said barrier layer comprises aluminum; and wherein said filmsurface protective layer comprises polyethylene terephthalate.
 15. Amethod of sealing a hard disk drive (HDD) having an internal space, themethod comprising: coupling a first cover to an enclosure base; mating asecond cover, positioned over said first cover, with said enclosurebase; positioning a laminated film to overlap with said second cover,wherein said laminated film comprises a heat sealant layer, a barrierlayer inhibiting egress of gas from said internal space, and a filmsurface protective layer protecting said heat sealant and barrierlayers, wherein said heat sealant layer is composed of a material thatforms a heat seal with a mating surface upon application of a sufficientamount of heat to said heat sealant layer; and forming a heat seal fromsaid laminated film to said second cover by applying heat and pressureto said laminated film.
 16. The method of claim 15, wherein positioningsaid laminated film comprises: positioning a planar portion of saidlaminated film substantially parallel with said second cover, andpositioning at least one sidewall portion of said laminated film, whichis substantially normal to said planar portion, to mate with acorresponding sidewall of said base; and further comprising bonding saidlaminated film to said sidewall of said base.
 17. The method of claim15, wherein positioning said laminated film comprises: positioning aplanar portion of said laminated film substantially parallel with saidsecond cover, and positioning at least one sidewall portion of saidlaminated film, which is substantially normal to said planar portion, tomate with a corresponding sidewall of said second cover and acorresponding sidewall of said base; and further comprising bonding saidlaminated film to said sidewall of said second cover and to saidsidewall of said base.
 18. The method of claim 15, wherein: said heatsealant layer comprises polypropylene; said barrier layer comprisesaluminum; and said film surface protective layer comprises polyethyleneterephthalate.
 19. A method of sealing a hard disk drive (HDD) having aninternal space, the method comprising: coupling a first cover to anenclosure base; positioning a laminated film to overlap with said firstcover, wherein said laminated film comprises a heat sealant layer, abarrier layer inhibiting egress of gas from said internal space, and afilm surface protective layer protecting said heat sealant and barrierlayers; mating a second cover, positioned over said first cover and saidlaminated film, with said base; and bonding said laminated film to saidsecond cover and to said base by applying heat and pressure to saidlaminated film.
 20. The method of claim 19, wherein said laminated filmfurther comprises a metal adhesive layer; and wherein bonding saidlaminated film includes bonding said metal adhesive layer to said secondcover and to said base.
 21. The method of claim 19, wherein: said heatsealant layer comprises polypropylene; said barrier layer comprisesaluminum; and said film surface protective layer comprises polyethyleneterephthalate.